The present invention relates to drinking water dispensers for animals, particularly for poultry, for controlling the supply of water to poultry or other animals.
One type of water supply system in common use for dispensing water to poultry is the suspension-type system in which a plurality of poultry drinking devices are supported in suspension over the ground. Illustrative of such suspension-type systems is that described in U.S. Pat. No. 4,852,522 which is incorporated by reference as if fully set forth herein. A popular poultry drinking device used in such systems is a nipple-type device which includes a downwardly-extending pin or valve stem which releases a small quantity of water whenever the pin or valve stem is pushed upwardly by the poultry. Another nipple-type device releases a small quantity of water whenever the pin or valve stem is pushed upwardly or is tilted by the poultry. In certain nipple-type devices, a weight is disposed directly above and in contact with the pin to ensure that a certain threshold force must be exerted before any water is released. Examples of such poultry drinking devices are described in U.S. Pat. Nos. 1,772,588, 2,594,968, 3,418,977, 3,477,471, 3,483,847, 3,582,006, 3,590,781, 3,602,197, 3,648,663, 3,669,077, 3,750,706, 3,750,628, 3,756,199, 3,982,706, 4,258,666, 4,491,088, 4,610,063, 4,610,221, 4,649,866, 4,790,264, 5,074,250, British Patent 1,514,448 and German Utility Model G8804053.4.
Presently known nipple-type drinking devices suffer from a number of disadvantages: Thus, many nipple-type drinkers are activated only by pushing the pin directly upwardly which makes it more difficult and time-consuming for the poultry to activate the device. In addition, the amount of force needed to activate the device is approximately constant regardless of the degree to which the pin is displaced; and while it is possible for a fully mature hen to obtain an adequate supply of water, chicks and weaker poultry may be unable to exert enough force on the pin to overcome the threshold force required to activate the device to release water. Further, the location of the weight directly above, and in contact with, the pin can act to "freeze" the pin in a tilted position and prevent the pin from returning to its normal untilted position following displacement; this may cause the water to drip to the floor of the coop where it can lead to the growth of mildew or to other unhealthy consequences.